1. Technical Field
The present invention relates to a card connector that is installed and used in various electronic equipment such as personal computers and portable terminals. More particularly, the invention relates to a card connector into which small-size cards such as memory cards of differing outer-dimension size and thickness can be inserted.
2. Related Art
Installed in various electronic equipment such as personal computers and portable terminals, card connectors have been used for insertion of small-size cards, etc., with built-in CPU or memory IC, etc., such as micro MMCs (multi media cards) or micro SD (super density) cards, so as to expand the capabilities of such equipment.
A typical example of such a card connector is set forth in JP-A-2003-197296. This card connector has a connector housing with a card insertion aperture at the front and a card holding cavity inside, and multiple contact terminals that are fitted in the inner part of the card holding cavity; the structure is such that two card types of differing size and thickness can be inserted through the insertion aperture. Also, a card sensing switch is provided in the housing, and the installation status of each card type can be sensed.
Another typical example of a card connector is set forth in U.S. Pat. No. 6,642,614. This connector has a connector housing provided with a card holding cavity whose front and top are open; multiple contact terminals that are fitted in the inner part of the card holding cavity; and a covering that covers the top opening of the connector housing; the structure is such that two card types of differing size and thickness can be inserted through the front opening.
According to these connectors, an insertion aperture is formed in the front of the connector housing, two card types of differing size and thickness can be inserted through the insertion aperture, and the cards' contacts are electrically connected to the connector's contact terminals.
However, with each of these card connectors, when assembled it is not possible to examine the internal structure of the card holding cavity, such as the shape of the holding cavity and the contact terminal array status, through the insertion aperture. Hence, a user inserting a card into the insertion aperture will consult the written instructions or procedure, etc., printed on the card and insert the card into the insertion aperture in accordance with such instructions. But such consultation operation is troublesome and annoying, so that sometimes the card will be inserted without performing such consultation; if such insertion is stopped mid-way, the card will be pulled out from the insertion aperture so as to invert its directional or obverse-reverse face orientation, then reinserted for another try. Failure to effect adequate connection via such insertion will entail a further insertion operation with the card turned the other way around, etc. Such connection work will be troublesome and annoying, and what is more, forcibly carrying out such inappropriate insertion could damage or break either the connector or the card. Concerning this, the connector set forth in JP-A-2003-197296 is provided with a sensing switch that senses the card installation status, and is therefore able to sense adequate installation status. But the above trial-and-error connection operations will still have to be carried out until adequate installation is effected, which means that the above problems will remain. Also, the card connector set forth in U.S. Pat. No. 6,642,614, although facilitating formation of the card holding cavity by having the top opening covered by a covering, has the same problems in the assembled state, because the covering is joined to the connector housing by means of bonding agent or the like.
Also, these card connectors are common connectors that are used with cards of differing thickness, which means that the distance between the contacts of the various cards and the connector's contact terminals will vary with the difference in thickness. As a result, when the resilience of the contact terminals has been adjusted to match a thick card, it will not be possible to impart the requisite resilience to the contact terminals with a thin card; and conversely, when the resilience of the contact terminals has been adjusted to match a thin card, then with a thick card the contact terminals will be excessively displaced, exceed their stress limit, and undergo plastic deformation.
Further, where not only the thickness but also the size, that is, the outer dimensions of the cards differs, the card holding cavity is formed to a size that matches large-sized, thick cards. Consequently, when a small-sized, thin card is housed in the card holding cavity, which is suited for a large-sized card, gaps equivalent to the differences in the size and thickness of the two card types will occur inside the card holding cavity. Because of this, the small-sized, thin card will be housed in an unstable condition inside the card holding cavity, and will move readily if some impact acts on the connector, possibly resulting in poor connection between the card and connector, and hence in failure.